FR2650356A1 - IMPROVEMENTS MADE TO MAN CHONS HYDRAULIC ANTI-VIBRATOR - Google Patents

Abstract

This is a hydraulic antivibration sleeve comprising two rigid tubular frames 1, 2 joined together by an elastomer body 3 forming with them two tight pockets A, B diametrically opposed and communicating with each other by a narrow channel, the 'all of said pockets and said channel being filled with a damping liquid, the portion of the elastomeric body which delimits the first pocket A having in axial section the general shape of a U or V open radially outwards, the narrow channel being composed of two narrow channels 9 which each extend along a transverse arc of a circle admitting as its axis the axis of the external tubular reinforcement 2, and each of these two arcs being located near this reinforcement and preferably close to an axial end of this frame. The first pocket is divided into two independent pockets A1, A2 into which respectively open the two narrow channels 9 assigned respectively to the damping of oscillations at different frequencies.

Description

Improvements brought to the hydraulic antivibration sleeves.

  The invention relates to anti-vibration sleeves

  hydraulic roofs comprising two rigid tubular frames surrounding each other and preferably of

  revolution at least in part, coaxial and concentric

  that at least under load, reinforcements joined together by an elastomer body shaped so as to form 'with them at least two waterproof pockets diametrically opposite in a direction D and communicating with each other by a narrow channel, all of said

  pockets and said channel being filled with a cushioned liquid

  weaver. Such sleeves are intended to be mounted between two rigid parts which can be joined respectively with the two frames and which are liable to undergo, relative to each other, oscillations oriented in the diametrical direction D, the assembly being arranged

  in such a way that for at least some of these oscillated

  tions, the liquid is pumped alternately from one of the pockets to the other and vice versa through the

  narrow channel, which creates in this liquid, for a

  given frequency of oscillations, frequency whose value

  F is directly related to the ratings of said channel, a pheno-

  proper resonance to dampen the transmission of

  these oscillations from one of the reinforcements to the other.

  The sleeves of the kind in question are for example-

  ple intended to be interposed between, on the one hand, a

  vehicle chissis and, on the other hand, the engine

  internal bustion or the front or rear axle of this vehicle

cule.

  The invention relates more particularly, by-

  mid the above sleeves, those in which the portion of the elastomer body which delimits at least one of the pockets has in axial section the general shape of a

  U or V open radially outwards and in the-

  which the narrow channel is composed of at least two narrow channels each extending, at least approximately and at least in part, according to a transverse arc of circle admitting for axis the axis of the external tubular reinforcement, each arc being located near this frame and

  preferably near an axial end of said arma-

  ture. Such sleeves have been described in the application

EUROPE Patent No. 0 248 714.

  In these sleeves, there are two narrow channels mounted in parallel between the same first pocket and a

same second pocket.

  The overall effect obtained by these two channels is then comparable to that which would be obtained by a channel

  unique in the sense that the sleeve considered allows a-

  basically kill oscillations corresponding to

a single given frequency.

  However, it may be advantageous to dampen with the aid of such a sleeve oscillations corresponding to two

separate frequencies.

  A solution to this depreciation problem

  double has already been proposed for anti-

  hydraulic bratory type "axial travel

  and not "diametrical" like the sleeves described above

  above, but still implementing like these the phenomenon of resonance of a liquid mass in a

narrow channel.

  Such supports with axial deflections include

  tent a rigid base, a rigid ring, a tight frustoconical elastomer wall joining the base to the ring, a flexible waterproof membrane connected to the ring, a rigid intermediate partition dividing the cavity delimited by the preceding elements into two chambers, namely a working chamber on the side of the frustoconical wall and a compensation chamber on the side of the membrane, a narrow channel making the two chambers communicate with each other and a damping liquid

  filling both rooms as well as the canal.

  The solution reported consists in replacing the working chamber, usually unique, of such a support with two independent working chambers.

  communicating respectively with the clearing house

  sation via two separate narrow channels, the dimensions of each channel being provided so as to ensure optimum damping of the support for oscillations of a given frequency and the values F1 and F2 of this frequency being different for the

two channels.

  In the embodiments which have been pro-

  posed to implement this solution, the cons-

  clearing of clearing houses, then concentrated

  triques, are relatively complicated and unreliable.

  The object of the invention is, above all, to remedy

these disadvantages.

  To this end, it takes advantage of the fact that, in the sleeves described above, there are already at least two separate narrow channels connecting the same first pocket. - know that delimited in part by the U or V portion of the elastomer body - with the same second pocket, these two channels being able to extend along two arcs

  different from the same circle or according to two arches

  leading to distinct parallel circles: here we divide the first pocket into. two independent pockets into which the two narrow channels open respectively and the dimensions of each of these two channels, dimensions corresponding to the optimum damping of oscillations of a given frequency, are such that the values F1 and F2 of this frequency are different for the

two channels.

  The division of the first pocket into two independent pockets is also very simple: in fact, this first pocket is delimited, on the one hand, by a

  portion of the external reinforcement or of a thin piece

  carried internally against this frame and, on the other hand, by a portion of the elastomer body disposed inside said frame and, to divide said pocket in two, it suffices to add to said body a waterproof veil molded with him and extending from

  from its central area to the tubular frame ex-

  dull. In advantageous embodiments, the second pocket is further itself divided into two compartments into which the two channels open out respectively, this division being produced in particular by a waterproof veil molded with the elastomer body and extending to from a central portion

  from this body to the external tubular frame.

  The invention comprises, apart from these arrangements

  main provisions, certain other provisions which are preferably used at the same time and which will be

  more explicitly question below.

  In the following, a preferred embodiment of the invention will be described with reference to

  drawing appended hereto in a way of course not limited

  tative. Figures 1 and 2 of this drawing show a

  hydraulic anti-vibration sleeve established according to the invention

  tion, respectively in axial section along I-I figure 2

  and in cross section according to II-II Figure 1.

  Figure 3 is a partial axial section of the

same sleeve according to III figure 2.

  The sleeve in question comprises: - an internal tubular metal frame of revolution 1, - an external tubular metal frame of revolution 2 which surrounds the frame 1 and which, for the mounted and loaded state of the sleeve, can be coaxial with this frame 1, the axes of the two armatures being in any case parallel to each other when the sleeve is at rest, and an elastomer body 3 connecting the two armatures 1 and 2 to each other, providing two watertight pockets A between them, B diametrically opposed in a direction D.

  The internal frame 1 is intended to be solida-

  risée with a spindle (not shown) which crosses it contiguously while the external frame 2 is intended

  to be secured with a bearing (not shown), this-

  the spindle and this bearing being secured respectively to two rigid elements between which it is desired to mount an anti-vibration support, elements such as a motor or vehicle suspension arm and that the chassis of this

vehicle.

  A part of the body'3, which is assumed here purely by way of illustration to be its upper half, has under load a shape in part of revolution around the axis common to the two frames 1 and 2 with an axial U-shaped half-section or of V, two grooves 4 open axially towards the outside of the sleeve being hollowed out in the two end faces 5 of said portion.

  This portion also includes two short arms

  dials 6 diametrically opposite or extending along a widely open V as can be seen in FIG. 2, arms which delimit with the faces 5 and the external frame 2 the chamber A. The portion of the body 3 which delimits the chamber B

  consists of a thin flexible membrane 7.

  This membrane is in the form of a curved strip in a semi-circle and slightly curved towards the axis. This strip has two semi-circular edges tightly connected to the external frame 2 and the two ends of said strip considered in the circumferential direction are connected to the radial arms 6, a pocket C open axially in the open air

  thus being formed between these arms and the membrane 7.

  Two circular sections 8 are attached to the two axial ends of the external frame 2, inside this frame, so as to form with

  the latter two narrow circular channels 9.

  In the illustrated embodiment, each profile 8 has in axial half-section the shape of a U open radially towards the outside and comprises a disc 81 projecting slightly towards the outside and crimped between an edge 21 folded inwards d 'an axial end of the external reinforcement 2 and the terminal edge opposite a perforated cylindrical sheath 10 forming a spacer and inserted contiguously in this

frame.

  This sheath 10 encloses the two profiles 8 contiguously so as to seal them tightly

radially outward.

  Said sheath is not continuous over its entire circumferential extent, but composed of two curved pieces or tiles between which the

  ends of the arms 6, as visible in FIG. 2.

  As can also be seen in FIG. 2, each of the two channels 9 opens laterally through orifices 11 in the two chambers A and B respectively. Instead of the chamber A being single and the two channels 9 opening into this chamber A being identical, as in the previous constructions,

  - here we divide room A into two compartments

  elements A1 and A2 by adding very simply to the body 3 in

  elastomer a web 12 extending between a central portion

  trale of the body 3 and the external reinforcement 2 or more

the sheath 10,

  - the two channels 9 are unblocked in res-

  pectively these two chambers A1 and A2, - and the dimensions of these two channels are given corresponding values. at optimum amortization

  corresponding oscillations & respectively two fre-

separate quences.

  These two frequencies are advantageously - a first frequency F1 of the order of 5 to Hertz corresponding to the "hash", that is to say to the tremors created by the irregularities of the ground on which the vehicle in question is moving, a phenomenon which l 'it is better to dampen as much as possible, and a second frequency F2 of the order of 25

  at 35 Hertz corresponding to vibrations due to the function

  engine idling when the vehicle is stationary, vibrations against which it is advantageous

  to create a minimum stiffness or stiffness.

  The two orifices 11 through which each channel 9 opens respectively into the chamber B and into the compartment A1 or A2 can be angularly spaced relative to each other around the axis of the sleeve of any desirable angle, this angle being for example of the order of 45 as illustrated, but which can be

  much larger and even greater than 180 or 270.

  As each profile 8 extends here over a complete circle, plugs (not shown) are introduced into this profile to delimit the ends of the channels -9.

  In Figure 2 we only see the mouthpieces

  res 11 of channel 9 serving compartment A2, this

  nal being housed in section 8 on the right in FIG. 1 the other channel 9, serving compartment A1, is housed in section 8 on the left of said FIG. 1, and its mouths in said compartment A1 are therefore not

not visible in Figure 2.

  According to a variant, the two channels 9 could be constituted by two distinct sections of the same profile 8, these two sections being able to open into the

  chamber B through the same orifice 11.

  One could envisage that at least one of the two channels 9 extends over more than 360 degrees, this channel is

  then having, in particular, in the form of a helix.

  The two compartments A1 and A2 could have identical and symmetrical volumes with respect to one plane, which could be the bisecting axial plane P of the large V formed by the arms 6 in cross section (FIG. 2), or again the bisector transverse plane Q of the V or U delimiting the internal face of, the chamber A above in an axial section (FIG. 1), the web 12, of generally flat shape, then having its mean plane coincident with said plane P or Q. But said mean plane of the web 12 can also be parallel to one of these planes or inclined on one of said two planes, while preferably remaining

axial or transverse.

  In the illustrated embodiment, the volumes

  mes of the two compartments A1 and A2 are different: it can be seen in FIG. 2 that the mean plane of the web 12, of generally flat shape, is substantially parallel to the plane

  P above, but offset from this plane.

  Following what and whatever the embodiment adopted, there is finally a hydraulic anti-vibration sleeve whose constitution and

  benefits result sufficiently from the above.

  As it goes without saying, and as it results from

  their already from the above, the invention is not limited

  in no way to those of its modes of application and implementation

  which have been more specifically contemplated; on the contrary, it embraces all variants, in particular those where the second chamber B would be, like chamber A, divided into two compartments served respectively by the two channels 9, in particular by an intermediate partition 13 molded from the body 3 and extending parallel to the axis of the sleeve and radially from the central zone of the membrane 7 to the external tubular reinforcement 2 or the sheath

  which lines this frame internally.

Claims (7)

  1. Hydraulic antivibration sleeve comprising two rigid tubular frames (1,2) surrounding each other and joined together by an elastomer body (3) shaped so as to form therewith   at least two waterproof pockets (A, B) opposite diametra-   slowly and communicating with each other by a narrow channel, all of said pockets and said channel being filled   of a shock absorbing liquid, the portion of the body in elastic   land which delimits at least one of the pockets (A) - hereinafter called "first pocket" - having in axial section the general shape of a U or V open radially outwards, the narrow channel being composed of '' at least two narrow channels (9) which each extend, at least approximately and at least in part, according to an arc of   transverse circle admitting the axis of the arma-   external tubular structure (2), each arch being located near said frame, characterized in that the first pocket (A) is divided into two independent pockets (A1, A2) into which the two narrow channels (9) open respectively and what the odds of each   of these two channels, dimensions corresponding to the   optimum oscillations of a given frequency, are such that the values (F1 and F2) of this frequency   are different for the two channels.   2. Sleeve according to claim 1, characterized in that each of the two transverse arcs of circle which extend the narrow channels (9) is   located near. of an axial end of the tubular reinforcement external area (2).   3. Sleeve according to any one of the claims.   cations 1 and 2, characterized in that the first pocket is divided in two by a waterproof veil (12) molded with the elastomer body (3) and extending to   from the central zone of this body to the arma- external tubular structure (2).   4. Sleeve according to claim 3, characterized in that the veil (12) of generally flat shape, has its   medium plane parallel to the axis of the sleeve.   5. Sleeve according to claim 3, characterized in that the veil (12) of generally flat shape, has its   mean plane perpendicular to the axis of the sleeve.   6. Sleeve according to any one of the preceding-   your claims, characterized in that the second   pocket (B) is also divided into two compartments in   which respectively open the two channels.   7. Sleeve according to claim 6, characterized in that the division of the second pocket is carried out by a sealed veil (13) molded with the elastomer body (3) and extending from a portion   center of this body to the tubular reinforcement ex- dull (2).